Electric switching installation



Aug. l1,` 1931. c. THUMIM 111.8011111: smi-'6111118 Ins'mnLATIoN Filed May 2. 1928 Inven'or- C'arl Thumm,

His ATTprneg.

Patented Aug. 11, 1931 ENT OFFICE CAR-L THUMIM, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GENERAL ELECTRIC 7':

COIVIIANY, A CGR'PORA'IION GF NEW YORK ELECTRIC SVJITCEII Application filed May 2,

My invention relates to installations of electric switches of the type in which the switch contacts operate in an insulating liquid contained in a closed vessel which to insure greater safety is rprovided with means to permit the quick relief of eiiecessive pressure in the casing.

More particularly my invention relates to means whereby the connection between a` switch casing and the means for conducting away the material discharged therefrom is automatically made or broken in accordance with the position of the switch. A further object of my invention is the provision of improved means where a plurality of switches are served by a common discharge conducting means for preventing material discharged into said means by one of the switches from escaping at the point at which another of the switches at that time may be disconnected.

'My invention will be better understood from the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the ap pended claims.

Referring to the drawings, Fig. l illustrates an installation of switches of the truck panel type embodying my invention; Fig. 2 is a detail thereof drawn to a larger scale; in Fig. 3 I have shown my invention applied to an installation of switches of what is commonly termed the metal clad type in which the switches are vertically movable to connect or disconnect them relative to the bus bars or feeders; Fig. 4 is a detail drawn to a larger scale of the structure shown in Fig. 3; in Fig. 5 I have shown my invention applied to a switch installa- NG INSTALLATION i923. Serial No. 274,664.

tion wherein the switches normally remain m fixed position; and Fig. 6 is a detail thereof.

The switches comprising the installations whichl I have illustrated are of the com` pletely enclosed liquid break type, the casings of which are constructed to withstand high internal pressure. In some cases the casings may be provided with gas discharge outlets connecting with gas cooling and separating means such for example as a gravel baiiie; in other cases the casing may be completely closed except for a very small or vent opening through which the internal and external pressure may gradually equalize.

The construction of the switch in either case is such that the casing will withstand with an ample `factor of safety all internal pressure produced under the normalrated use` might soon be produced withconsequent disastrous results. To provide against. such, the switch casing may have a relatively large discharge opening formed therein normally closed by a diaphragm which is 'constructed to be ruptured upon the Aoccurrence v.

of a predetermined pressure in the casing. An arrangement ofthis character is disclosed and claimed in the copending application of `William K. Rankin, Serial No.

204,687, filed July 1l, 1927. Because of the(v danger to life and property of the gas and liquid which would be discharged. from a switch so provided, I have provided means for conducting away the discharged material to a point outside the building in which the switch is housed or at least to a point where it cando no harm. Where a number of switches are arranged together, as for example, in a row, I provide a duct having a series of laterals or branches forminga manifold to which I connect the discharge ino outlets of the several switches when the switches are in their normal or operating positions.

In Figs. 1 and 2 where I have shown my invention applied to a switch of the truck panel type comprising the housing 1 and cooperating truck mounted switch 2, the duct 3 is arranged in fixed position in the housing 1 behind the plate Li. The lateral or switch connecting pipe 5 extends through and is shown secured to this plate by means of the flange 6 and bolts 7. Secured in the top of the switch casing 9 is the discharge pipe 10 terminating in the elbow 11. At some point in the discharge pipe or elbow, I place a diaphragm which will rupture when the pressure in the switch casing' reaches a predetermined value and thus give instant and unrestricted relief to the pressure. I preferably employ for this purpose the diaphragm or disk 12, which is constructed of sheet metal, such for example, as copper, and is deformed so that one face is convex and the other concave, the curvature of the two faces preferably being spherical. The disk is shown mounted in the separate ring 13, which has an internal shoulder engaging the disk on the side opposite the switch casing and to which the disk is firmly secured, for example, by means of solder. Ring 13 is shown bolted between the pipe 10 and the elbow 11, suitable gaskets being provided to make tight joints. Disk 12 is arranged with its convex side toward the switch. `When the pressure in the switch casing reaches the value at whichit is desired that the diaphragm should give way it suddenly ruptures and reverses its curvature. In this condition it is bodily blown out of the elbow into the manifold.

The outer end of the elbow 11 terminates in the flange 15, which has a flat end face adapted to abut against a similar flat face on the ring 16 slidably mounted on theadj acent end of pipe 5. Ring 16 is yieldingly held in its outermost position on the pipe by smallV coil springs 17 surrounding the bolts 18 and carries the packing ring 19 engaging the pipe 5 thereby making a substantially gas-tight fit. Then the truck switch 2 is rolled into its housing in position to cause the disconnect contacts to engage, the two rings 15 and 16 abut each other compressing the coil spring 17.

Where several switches are arranged to discharge into the same manifold an element of danger presents itself in that should one of the switches be in trouble and discharge into the manifold at a time when a second switch is disconnected from the manifold, a blast of gas might be discharged from the manifold into the room at the point of disconnection of the second switch. To prevent the possibility of such an occurrence, I have shown the curved disk 2l which is of the same construction as the disk 12 and similarly mounted in the ring 16 but turned with its convex face toward the manifold. As so arranged the disk 9,1 will effectively resist whatever gas pressure may exist in the manifold due to a discharge thereinto of a switch, yet will present but slight opposition to the discharge of gas into the manifold from the particular switch with which it is associated. Relatively small amount of pressure only on the concave side of the disk is suiiicient to dislodge the disk and blow it into the manifold.

The form of my invention shown in Figs. 3 and 4 differs from that of Figs 1 and 2 only in the type of switch with which it is used. Each switch 24 in this case is supported in a fixed framework 25 in which it is arranged to be moved vertically to effect connection and disconnection of the disconnecting contacts enclosed in the tubes 26. The manifold in this case is shown at 27 supported in the upper portion of the framework 25. rIhe connection between the switch casing and the manifold is similar to that of the form just described except that the elbow Q8 is shown somewhat longer and directs the discharged material upwardly into the lateral 29 of the manifold 2T. lVhen the switch is lowered the connections be tween the elbow 28 and lateral 29 separate as will be obvious from an inspection of the drawings.

In the form of my invention illustrated in Figs. 5 and G, each switch 30 is supported in fixed position. The connection between the manifold 3l and the switch casing is like that shown in the previous figure with the exception that the lateral 32 and elbow 33 are clamped together by the bolts 34. In:

this case the ring 35 supporting the diaphragm 21 is secured by the screws 3G to the flange on the lateral. lVhen the switch is to be removed for inspection or is to be replaced by another, bolts 34 are removed l which allows elbow 33 still fixed to the switch to separate from the ring 35. The latter ring remains attached to the lateral, and since it retains the diaphragm 21 a gas discharge from the manifold need not be;

said discharge passages, and pressure relief means mounted in and normally closing each of said connections collapsible in response to predetermined pressure within a switch casing, said means including pressure resisting means normally closing said duct at any detachable connection when the corresponding switch casing connection is detached and preventing discharge from an affected switch casing through said duct into an unaffected switch casing.

2. Switching apparatus comprising a fixed structure, a plurality of switches movable relatively thereto, a discharge manifold supported by said fixed structure and having a connection with each of said switches, a joint in each of said connections at which the parts associated with the switch and the manifold separate when the switch is moved from the fixed structure and collapsible means normally closing` each of said connections for preventing the escape of material at the joint from. the manifold when the switch is removed and for preventing discharge from one switch casing into another.

3. Switching apparatus comprising a fixed structure, a pli'lrali'ty of switches inovable relatively thereto, a discharge manifold supported by the fixed structure, discharge pipek for connecting each of the switches with the manifold, each pipe having a yielding joint therein adapted to separate when the corresponding switch is moved to a predetermined position relative to the fixed structure, closing means in said pipe arranged on one side of said joint constructed to oppose passage of gas from said switch to said discharge manifold until a predetermined pressure thereof is reached and closing means on the opposite side of said joint constructed to oppose passage of gas from said manifold to said switch.

4. Switching apparatus comprising` a plurality of switches having closed casings, a discharge duct common to said switches, discharge pipes connecting the respective casings with said duct, each of said pipes having a joint therein at which the adjacent portions of the pipe separate when the switch is removed and a concavo-conveX disk closing each portion of said pipe, said disks being arranged with their convex faces turned away from said joint so that one of said disks prevents exhaust of material from said casing until the pressure therein has reached a predetermined value and the other of said disks prevents exhaust of material from said discharge duct when the switch is removed.

5. Switching apparatus comprising a fixed structure having disconnecting contacts, a movable switch having cooperating contacts and having an enclosing casing provided with an emergency discharge pipe, a cooperating fixed discharge pipe supported by said structure, one of said pipes having a ring slidably mounted thereon for engagement with the adjacent end of the other pipe, means for resiliently holding the ring in the forward position, and a concavoconvex disk mounted within said ring for resisting passage of material through the discharge pipe in one direction.

6. Switching apparatus comprising a plurality of switches having closed casings, a discharge duct common to said switches, discharge pipes connecting the respective casings with said duct when said switches are in their normal operating positions, means in each of said pipes for preventing discharge from the switch casings until a predetermined pressure has been reached, and means interposed between said lastnamed means and common duct for preventing discharge from said duct into a switch casine'while permitting substantially unobstructed fiow of material from the casing.

7. Switching apparatus comprising a plurality of switches having closed casings, a discharge duct common to said switch casings, discharge pipes connecting the respective casings with said duct when said switches are in their normal operating positions, a concave-convex disk in each of said pipes for preventing discharge therethrough of gas and oil from the corresponding switch casing until the pressure therein has reached a'predetermined value, and a concavo-convex disk interposed between said first-named disk and said common duct for preventing discharge from said duct into an unaffected switch casing while permitting substantially unobstructed flow of material from the casing, said concave-convex disks arranged with their concave faces towards leach other.

In witness whereof, I have hereunto set my hand this 30th day of April, 1928.

CARL THUMM. 

